The devices for moistening an adhesive strip that are the most widespread, because they are the simplest, comprise a moistening element constituted by a sponge or a felt. It is known that this type of moistening element does not have long life. European patent application No. 0 293 316 describes a device for moistening adhesive labels that comprises a moistening element in the form of a brush constituted by a sheet of bristles. The brush is placed in a vessel filled with moistening liquid suitable for diluting the adhesive. The bottom portion of the brush is immersed in the moistening liquid which is maintained at constant depth. The top portion of the brush as wetted by the liquid by capillarity is kept in contact with the adhesive-coated face of the labels as they run past the brush. Although such a brush has longer life than a sponge or a felt, it suffers from the drawback, over a period of time, of not distributing moistening liquid uniformly over the adhesive face of the labels because it picks up adhesive. The effect of wiping the adhesive face of the labels over the ends of the bristles of the brush is to cause adhesive to be deposited between the bristles of the brush. As a result the brush clogs up with adhesive that remains trapped between its bristles without any possibility of being moved as the labels go past. This gives rise to a poor transfer of moistening liquid onto the labels, with some portions of the adhesive-coated face of the labels being cleaned, so that in the course of time the moistening of the labels is not uniform.
The object of the invention is to provide a device for moistening a flexible strip, the device including a moistening element that does not present the above-mentioned drawbacks.